Girls with idiopathic precocious puberty have been receiving treatment with the luteinizing hormone releasing hormone a(LHRHa) for the past five years. Slow growth (less than 5cm/yr) has been observed in these girls during LHRHa therapy when their BA = 10-13 yrs. We propose to study 24 hr. growth hormone(GH) secretion in five girls before and during LHRHa therapy and in five girls without therapy to determine whether or not a change in GH secretion is responsible for the slow growth.